Recessed chain-track assembly for dishwashers

ABSTRACT

A conveyor system for propelling dish racks on a pair of slide tracks through a dishwasher by means of lugs carried on a single, rearwardly disposed conveyor chain which rides on a separate chain rail positioned directly below the rearmost one of the aforesaid pair of slide tracks, the chain rail supporting the drive run of the conveyor chain on a top external surface thereof and the return run of the conveyor chain on a lower internal surface thereof, the lower internal surface of the chain rail being of a lesser width than the top external surface thereof thereby permitting the lugs on the return run of the chain to travel along the edge of the lower internal surface unobstructed, and means being associated with each of the aforesaid pair of slide tracks for tightening and locating the track assembly against the main body of the dishwasher while still permitting both of the slide tracks to be directly removed from the dishwasher with a minimum of effort.

United States Patent 3,289,682 12/1966 Naslund 3,381,800 5/1968 Everett et al.

ABSTRACT: A conveyor system for propelling dish racks on a pair of slide tracks through a dishwasher by means of lugs carried on a single, rearwardly disposed conveyor chain which rides on a separate chain rail positioned. directly below the rearmost one of the aforesaid pair of slide tracks, the chain rail supporting the drive run of the conveyor chain on a top external surface thereof and the return run of the conveyor chain on a lower internal surface thereof, the lower internal surface of the chain rail being of a lesser width than the top external surface thereof thereby permitting the lugs on the return run of the chain to travel along the edge of the lower internal surface unobstructed, and means being associated with each of the aforesaid pair of slide tracks for tightening and locating the track assembly against the main body of the dishwasher while still permitting both of the slide tracks to be directly removed from the dishwasher with a minimum of effort.

RIECESSEI) CHAIN-TRACK ASSEMBLY FOR DISHWASHERS BACKGROUND OF THE INVENTION 1, Field of the Invention Our invention relates to dishwashing equipment and more particularly to an improvement in conveyor chain and traclt assembly means for use primarily in raclt conveyor type commercial dishwashers.

2. Description of the Prior Art Commercial dishwashers of the rack conveyor type are commonly provided with some means of automatically conveying dish racks through the various wash and rinse chambers or modules thereof. In accordance with the conventional method of operation of this type of dishwasher, soiled dishes are placed in the aforesaid standard dish racks and the latter are fed to the entrance end of the dishwasher whereupon they are engaged by the aforementioned automatic conveying system of the dishwasher. As the dish racks are then transported through the dishwasher, the dishes carried thereby are cleansed such that when the aforesaid dish racks reach the exit end of the dishwasher, the dish racks may be removed therefrom along with the dishes which now being clean are ready for reuse.

A major requirement in the design of this type of conveyor system as well as the tracks on which the dish racks slide is to keep the area between the tracks free from obstructions. The reason for this is twofold. The more obvious of which of course is that it is necessary for continued efficient operation of the dishwasher that the dish racks be unimpeded in their travel through the dishwasher. Any obstruction substantial enough to impede the progress of the dish racks through the dishwasher could conceivably cause severe damage not only to the racks themselves and the dishes carried thereby but also to the drive mechanism of the conveyor system, etc. More importantly however the area between the tracks must be maintained free of obstructions in order to ensure that the dishes are properly cleaned in their passage through the dishwasher. The cleansing action normally provided in this type of dishwasher conventionally involves the employment of at least one pair of opposing wash spray water means with one of these means being supported adjacent the top of the wash compartment of the dishwasher and the other below the horizontal plane of the above-referenced slide tracks. Combined full operation of both of these wash spray water means is required in order to achieve the proper sanitizing of the dishes. Any obstruction between the tracks which impairs the cleansing action of either or both of the wash spray water means on the dishes cannot be tolerated since the operation of the dishwasher and the cleaning effect provided thereby are closely governed by one or more of the various local and/or national sanitation codes applicable to the use of such dishwashers particularly when located in commercial establishments.

Also of prime importance insofar as the operation of such dishwashers is concerned is the access provided for the purposes of cleaning the interior of the dishwasher as well as the interior assemblies thereof including the conveyor drive system. Prior art conveyors which conventionally employ dual front and rear drives by virtue of the presence of the front drive necessarily have an obstruction at the front interior of the dishwasher which limits access to the rear drive particularly and the rear interior generally of the dishwasher. In addition the nature of a dual chain or pawl drive conveyor system is such that it is not easily removable even if this were desired to afford the access required to effectively accomplish the aforesaid task of cleaning and maintaining the various internal components of the dishwasher.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a novel and improved conveyor chain and track assembly for commercial dishwashers wherein the front slide track for the dish racks is directly removable with a minimum of effort thereby facilitating the cleaning of the conveyor chain and track assembly as well. as the interior and the rearwardly positioned other components of the dishwasher.

It is another object of the present invention to provide such a conveyor chain and track assembly for commercial dishwashers which is so mounted in a dishwasher as to in no way interfere with the cleansing effect provided by the lower wash spray water means thereof as do center chain drive or center pawl drive conveyor systems which previously have been commonly utilized in prior art dishwashers of similar type.

A still further object of the present invention is to provide such a conveyor chain and track assembly for commercial dishwashers wherein all of the moving parts thereof are located at the rear of the dishwasher so as to limit the possibility of any injury occurring to personnel due to their coming into contact with such moving parts while the dishwasher is operating.

Yet another object of the present invention is to provide such a conveyor chain and track assembly for commercial dishwashers wherein the conveyor chain is supported below the horizontal plane of the slide tracks out of the path of any possible accidental contact with the dish racks passing thereabove and with only the lugs carried by the conveyor chain protruding above a slide track whereby to permit the lugs to engage a dish rack.

Yet a further object of the present invention is to provide such a rack chain and track assembly for commercial dishwashers wherein the rear slide track is easily removable without the use of tools for purposes of access to and cleaning of the conveyor chain.

SUMMARY OF THE INVENTION In accordance with a preferred form of the present invention there is provided a conveyor chain and track assembly for a rack conveyor type commercial dishwasher including spaced parallel slide tracks which receive racks containing articles to be washed. The conveyor chain and track assembly further in cludes a single conveyor chain located at the rear of the dishwasher below the rear slide track and having lugs upstanding therefrom which engage the dish racks to move the latter through the dishwasher. The conveyor chain lugs protrude above the level of the rear slide track adjacent thereto to engage the lower edges of the dish racks. A chain support rail is located directly below the rear slide track and is of channelshaped configuration having an upper rail section with a top surface supporting the drive run of the chain and having a lower rail section with a top surface supporting the return run of the chain. The lower rail section is of shorter extension than the upper rail section to permit the lugs 0n the return run of the chain to move unobstructed. Both the front and rear slide tracks are directly removable with a minimum of effort and the conveyor chain drive is located rearwardly of the rear track, all of which facilitates cleaning of the slide tracks and of the interior and rear parts of the dishwasher without obstruction and without risk of injury to personnel.

The invention will be more fully understood from the following detailed description and its scope will be pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view of a dishwasher having a conveyor chain and track assembly in accordance with the present invention;

FIG. 2 is an end elevational view showing the entrance end of the dishwasher of FIG. I;

FIG. 3 is an end view of the conveyor chain and track assembly of the dishwasher of FIGS. 1 and 2 in accordance with the present invention illustrated in association with a motor driven chain drive therefor;

FIG. 4 is a plan view of the conveyor chain portion in accordance with the present invention of the conveyor chain and track assembly of FIG. 3;

FIG. is a cross-sectional view of the conveyor chain of FIG. 4 taken substantially on the line 5-5;

FIG. 6 is a side view of the single run of conveyor chain and the chain drive therefor in accordance with the present invention;

FIG. 7 is a perspective view of one of the lugs of the conveyor chain of FIG. 6;

FIG. 8 is a perspective view of the front slide track of the conveyor chain and track assembly of the dishwasher of FIGS. 1 and 2; and

FIG. 9 is a plan view of a typical dish rack for use with the dishwasher of FIGS. 1 and 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIGS. 1 and 2 of the drawing, the invention is shown as incorporated in a rack conveyor type commercial dishwasher generally designated by reference numeral 10, and which comprise a housing 11 divided into a pair of washing compartments l2 and 13 integrally arranged in side-by-side relation. In accordance with one embodiment of the invention, the compartment 12 may take the form of a conventional prewash section as it is commonly referred to in the art wherein the soiled dishes are initially given a preliminary wash to remove the bulk of the food particles which commonly remain on the dishes even after the latter have been scraped prior to being fed into the dishwasher 10. Compartment 12 may however also take the form of a conventional power wash section. Whereas compartment 13 on the other hand normally constitutes the spray compartment wherein the so-called actual cleansing of the dishes takes place, it may also function as a rinse compartment in the case wherein compartment 12 constitutes a power wash section. Although not shown it is to be understood that normally in accordance with conventional practice the compartment 13 when employed as the aforesaid spray section includes at its exit end a rinse means wherein the dishes after being washed are subjected to a final rinse with water which is at a maximum sanitizing temperature just prior to their exit from the dishwasher 10.

The compartments 12 and 13 are each closed with a door 14 and 15, respectively, vertically slidable in channels (not shown) suitably provided for this purpose. Each of the doors l4 and 15 is provided with a full-width door lift 16 and 17, respectively, appropriately recessed so as not to present any protrusions which might accidentally be engaged by equipment or personnel passing closely adjacent thereto, or which might catch on the clothing of the operator of the dishwasher 10. The full-width door lifts l6 and 17 allow the lifting action with respect to the doors l4 and 15 to take place along the entire front of the dishwasher while the doors 14 and permit an operator to readily reach all areas within the dishwasher interior. The dishwasher 10 is preferably supported on a plurality of bulletlike legs 18, each individually adjustable, which are suitably secured to the undersurface of the housing 11 at each of the four corners thereof.

The requisite water inlet means 19 and associated piping therefor are located in juxtaposed relation to the rear and top of the housing 11 of dishwasher 10 as best seen with reference to FIGS. 1 and 2 of the drawing. Suitable wash tanks are positioned in conventional fashion behind the front tank panels 20 and 21 of housing 11 for the purpose of receiving the excess of the wash water which has been sprayed on to the dishes, the latter spraying being accomplished by means of wash spray water means more fully referred to hereinafter. The water which flows into the aforesaid wash tanks is normally recirculated by means of a pump (not shown). Inasmuch as the manner in which water is circulated and/or recirculated in a dishwasher such as the dishwasher 10 is well known to those skilled in the art and the fact that the manner in which this is accomplished is only indirectly related to the subject matter of the present invention, it has not been further described herein.

As depicted in dotted lines in FIG. I of the drawing, dishes 23 suitably retained in rack 24 are fed into the dishwasher l0 in the direction of arrow 25, i.e., from right to left as viewed with reference to the aforesaid FIG. 1. Suitable flap members 26 are preferably positioned in the entrance opening 27 and also in the exit opening (not shown) located at opposite ends in the housing 11 of dishwasher l0. These flap members 26 are primarily provided for the purpose of substantially closing both of the aforesaid openings so as to minimize the escape of wash water to the exterior of the dishwasher 10. The flap members 26 selected for use for this purpose are of course flexible enough to permit the rack 24 to be passed into the interior of the dishwasher 10 without occasioning any damage to the dishes 23 supported in the rack 24.

A watertight control console 28 is suitable supported on the housing 11 in juxtaposed relation to the compartment 12 at the entrance end of the dishwasher l0. Dials, switches, and indicators all generally designated by the same reference numeral 29 appropriate to the operation of the dishwasher 10 are positioned on the vertical panel 30 of control console 28 which is preferably inclined at a slight angle for easy readability of the instruments positioned thereon. A protective cover 31 precludes excessive drippage of water on to the inclined panel 30, and also assists in preventing abuse to the console 28 which might be occasioned by the loaded racks 24 which pass in close relation thereto as they are being fed into the interior of the dishwasher 10.

The wash spray water means previously mentioned hereinabove preferably comprises an upper and a lower spray box assembly 32 and 33, respectively, which are depicted in dotted lines in FIG. 2 of the drawing. The respective upper and lower spray box assemblies 32 and 33 are essentially identical both in structure and method of operation, although they often differ insofar as size is concerned. Each of the aforesaid spray box assemblies includes a spray box 34 and a spray plate or cover 35 therefor, the latter being releasably secured to its corresponding spray box by suitable means (not shown). The latter method of mounting the spray plates 35 to the spray boxes 34 provides an improved means for facilitating the cleaning of the spray boxes and particularly the spray plate as such cleaning is required, in a manner more fully described and illustrated in the copending patent application, Ser. No. 799,752, now U.S. Pat No. 3,568,935, of R. L. Hoffman, which is assigned to the same assignee as the present invention. Each of the spray plates 35 preferably has several parallel semicylindrical protrusions 36 formed therein each of which contains a plurality of spaced slots (not shown) from which the wash water issues in the form of a spray which has a pattern, velocity, and flow sufficient to constitute a cleansing spray having optimum cutting force when applied to the dishes passing therethrough.

FIG. 3 illustrates an end view of the conveyor chain and track assembly, generally designated by reference numeral 37, 0f the dishwasher 10 of FIGS. 1 and 2 in accordance with the present invention. As best understood with reference to the aforesaid FIG. 3,. the racks 24 are moved through the dishwasher 10 by means of the conveyor chain 38 of conveyor chain and track assembly 37. Conveyor chain 38 has a plurality of lugs 39 projecting outwardly therefrom at suitably spaced intervals which engage appropriate portions of each of the racks 24 thereby causing the racks 24 to move with the conveyor chain 38 as the latter is caused to move. One such lug 39 is illustrated in FIG. 7 of the drawing.

The racks 24 typically employed with rack conveyor type commercial dishwashers are often made of a suitable plastic material, and as illustrated in FIG. 9 of the drawing include four sidewalls 40 and a base 41. The base 41 of such racks 24 is commonly formed with a ladderlike portion 42 extending transversely across the base 41 adjacent each of two opposing sidewalls 40 and also along the center of the base 41. The spacing between the rungs 42a of each of the parallel extending ladderlike portions 42 is small enough to preclude the passage therethrough of dishes, etc., i.e., the items desired to be retained in the racks 24. On the other hand the spacing is sufficient to permit the entrance of a conveyor chain lug between each pair of successive rungs 42a. By providing each of the racks 24 with three such parallel extending ladderlike portions 42, the same racks are interchangeable between rack conveyor type dishwashers which have a center drive conveyor system and those which utilized a conveyor system having conveyor chains located at both the front and rear of the dishwasher. Further the racks 24 being symmetrical along the axis of the ladderlike portions 42, the racks 24 are reversible end-for-end thus obviating any need for concerning oneself with the proper orientation of the front of the racks 24 when loading the latter with dishes, etc. Typical racks having this construction are manufactured by William Hodges and Company, Inc. of Philadelphia, Pa.

Referring now more particularly to FIGS. 3, 4, and 6 of the drawing, the conveyor chain 38 is driven through drive shaft 43 on which is suitable supported a drive sprocket 44. The drive sprocket 44 in turn is driven by an external drive chain 45 which has one end passing around the drive sprocket 44 and the other end around sprocket 46. As illustrated in FIG. 6 of the drawing, the drive chain 45 preferably also passes around a pair of idler sprockets, 47 and 48, respectively, provided in accordance with conventional practice for the purpose of ensuring proper tensioning and/or operation of the external drive chain 45. The sprocket 46 is mounted on drive shaft 49 for rotation therewith, the latter drive shaft being caused to rotate by motor 50 through preferably a conventional gearbox (not shown). The motor 50 and associated gearbox (not shown) are mounted in accordance with the preferred embodiment of the invention in the housing 111 in the area below the level of the aforementioned wash tanks of the dishwasher 10. As viewed with reference to FIG. 3 of the drawing a suitable housing 51 enclosed the drive chain 45 to prevent any accidental contact therewith by personnel and/or equipment. It should further be understood that the ON and OFF controls for controlling the operation of the drive chain 45 and thereby the conveyor chain 38 are normally included among the dials, etc. located on the inclined panel 30 of the watertight control console 28.

As best understood with reference to FIG. 4 of the drawing, power is transmitted to conveyor chain 38 by the conveyor sprocket 52 which is mounted on drive shaft 43 for rotation therewith by suitable means such as pin 53. The conveyor sprocket 52 is positioned on drive shaft 43 intermediate the leg portions 54a and 54b of U-shaped support bracket 54, each of the leg portions 54a, 54 b of course being provided with suitable openings (not shown) to permit drive shaft 43 to extend therethrough. Externally of leg portion 54a but in juxtaposed relation thereto, drive shaft 43 is preferably provided with a thrust washer 55, and adjacent the washer 55 there is also retained on the drive shaft 43 a collar 56 by suitable means such as pin 57. Further, a bearing 58 is mounted on the drive shaft 43 in juxtaposed relation to the internal surface of leg portion 540 of U-shaped support bracket 54 by suitable means such as screws or rivets 59. Externally of leg portion 54b of supporting bracket 54 there is provided on drive shaft 43 a bearing 60 which houses a seal (not shown) internally thereof. In addition gasket 61 having an opening therein for passage of drive shaft 43 is preferably supported on the outer face of bearing 60. The assembly comprising bearing 60 and gasket 61 is mounted on leg portion 5412 by screws or rivets 62 similar to the aforementioned screws or rivets 59. The bearings 58 and 60 are intended to provide support and lubrication for the drive shaft 43. Screw 63 having nuts 64 at either end thereof may be provided as shown in FIG. 4 of the drawing to assist in retaining the leg portions 54a and 54b of U- shaped support bracket 54 in proper relation with respect to each other as well as the conveyor chain 38, etc.

With further reference to FIG. 4 of the drawing, it is seen that at its other end, i.e., the idler end, conveyor chain 38 passes around idler sprocket 63 which is supported on shaft 64 by means of pin 65. Here also, idler sprocket 63 is positioned intermediate the leg portions 66a and 66b of U-shaped support bracket 66, the latter being provided with suitable openings (not shown) to permit the shaft 64 to extend therethrough. A pair of adjustably mounted bearing 67 and 68 which receive the opposite end portions of shaft 64 are suitably supported adjacent the leg portions 66a and 66b, respectively, of U-shaped support bracket 66. The abovereferenced adjustment is accomplished through the use of a pair of angle brackets 69 and 70, each of which have one end 69a and 70a, respectively, mounted by means of screws 7ll and nuts 72 on leg portions 66a and 66b, respectively, of U- shaped support bracket 66. The other end of each of angle brackets 69 and 70, Le. end portions 6% and 70b, respectively, receives a screw 73. Byloosening the nut 74 which is associated with each of the screws 73 the idler end assembly of conveyor chain 38 including idler sprocket 63 may be moved in the horizontal plane of the upper run of the conveyor chain 38 to permit the conveyor chain 38 to be tightened as necessary. It is to be understood that after the requisite amount of tightening has been achieved, the nuts 74 are retightened to ensure that the conveyor chain 38 remains in the desired tightened condition. In addition, it is to be further understood that although not shown the leg portion 66a and 66 b are of course provided with suitable conventional means to permit the aforesaid relative adjustment movement thereof to take place.

Referring now to FIGS. 4 and 5 of the drawing, the upper and lower runs of conveyor chain 38 are supported on a chain support rail 75 which is secured at its opposite ends to U shaped support brackets 54 and 66, respectively, by suitable means such as screws 76 and nuts 77. Spacers may be interposed, if found desirable, between the respective leg portions of U-shaped support bracket 54 and 66 and the corresponding sidewall portions of chain support rail 75. As seen most clearly with reference to FIG. 5, chain support rail 75 comprises a generally L-shaped upper flange 78 and a lower horizontally extending flange 79 interconnected by a vertically extending medial portion 80. The top surface 780 of upper flange 78 supports the drive run of the conveyor chain 38 while the top surface of lower horizontally extending flange 79 supports the return run of the chain 38. The lower horizontally extending flange 79 is of shorter horizontal extension than the top surface 78a of L-shaped upper flange 78 in order to permit the lugs 39 of conveyor chain 38 on the return run of the chain 38 to return unobstructed. Thus, as illustrated in FIG. 5 of the drawing the lugs 39 of the return run of conveyor chain 38 extend downwardly adjacent to but spaced from the outermost edge portion of lower horizontally extending flange 79.

In accordance with the preferred embodiment of the invention, for purposes primarily of imparting some measure of protection to as well as protection from the lower run of conveyor chain 38, an L-shaped member 81 is provided having one end thereof suitably secured such as by screws or rivets 82 to the vertically extending medial portion of chain support rail 75. At its other end, the L-shaped member 81 has a right angle member 83 fastened thereto by means of a screw 84 threaded into a suitable opening (not shown) provided therefor in the member 83. Thus, the lower run of conveyor chain 38 moves in effect in a substantially closed compartment. Any suitable securing means such as for example the right-angle members 85 illustrated in FIG. 4 of the drawing may be provided for the purpose of removably mounting the chain support rail 75 and the conveyor chain 38, etc., to the housing ill of dishwasher 10 adjacent the rear wall thereof.

The other major component of the conveyor chain and track assembly generally designated by reference numeral 37 comprises a pair of tracks spaced in opposing relations, i.e., front track 86 and rear track 87, respectively. Referring to FIG. 8, the front track 86 comprises an L-shaped track rail 86 having a vertical portion 88a and a horizontal portion 8812 extending at right angles to each other. For purpose of assisting the entrance of dish racks 24 to an their exit from from track 86, the respective ends 88c of vertical portion 880 may be flared outwardly as seen in the aforesaid FIG. 8. A pair of downwardly extending support members 89 are adjustably secured at one end to the undersurface or horizontal portion 88b adjacent the opposite ends thereof by suitable means such as counter sunk flathead machine screws 90 and nuts 91. The other ends of the pair of downwardly extending support members 89 are suitably retained such as by welding preferably on the respective end walls of the housing 11 of dishwasher 10.

As seen with reference to FIG. 5, the rear track 87 comprises an L-shaped track rail 92 essentially identical in construction to the L-shaped track rail 88 of front track 86 illustrated in FlG. 8. That is, the track rail 92 has a vertical portion 920 and a horizontal portion 92b extending at right angles to each other. Preferably the respective ends of vertical portion 9211 are also flared outwardly in order to facilitate the "entrance of dish racks 24 to and their exit from rear track 87 A plurality of weld studs 93 are provided extending outwardly in spaced relation from the rear of vertical portion 92 a of rear track 87. Each of the weld studs 93 is intended to pass through a slotted opening suitably provided therefor in upwardly extending portion 94 of chain support rail 75. Additionally each of the weld studs 93 is received in an opening provided for this purpose in a suitable mounting bracket (not shown) preferably secured to the inside surface of the rear wall of housing 11 of dishwasher 10. By the use of wingnuts threaded on the weld studs 93, it has been found that the rear track 87 may be tightly mounted in the desired position solely by hand,-.

i.e., without the need for using any tools.

Proceeding now to a description of the method of operation 7 (not shown). From the soiled dishes table, a dish rack 24 loaded with soiled dishes 23 is fed to the entrance end of the dishwasher 10. With the conveyor chain 38 running the aforesaid dish rack 24 is thereupon engaged by one or more lugs 39 of conveyor chain 38. The lugs 39 will normally engage rungs 42a of ladderlike portion 42 of dish rack 24 to provide the interengagement between dish rack 24 and conveyor chain 38 although it is equally conceivable that the lug 39 may also engage the front or rear wall 40 of the dish rack 24. In any event, with the dish rack 24 so engaged by the lugs 39, the dish rack 24 is slid along through the length of the interior of the dishwasher 10 on front and rear tracks 86 and 87 respectively, by the conveyor chain 38 as the latter moves therethrough. During the course of this movement, the dishes 23 are carried through compartments l2 and 13 wherein suitable wash water is applied thereto by one or more pairs of upper and lower spray box assemblies 32 and 33, respectively, through whose combined cleansing action the dishes are cleaned. Prior to exit from the dishwasher 10, the dishes are given a final rinse with water which is at a maximum sanitizing temperature. As the dish rack 24 passes through the aforesaid final rinse station, the conveyor chain 38 begins its return run whereupon the lugs 39 automatically disengage themselves from the dish rack 24. The dish rack 24 is then passed on to the aforementioned clean dishes table (not shown) where the dishes 23 may be unloaded from the dish rack 24. It is to be understood that in accordance with the normal operation of the dishwasher 10, a number of dish racks 24 will be simultaneously carried in suecession through the interior of compartments l2 and 13 by conveyor chain 38.

When cleaning of the various interior components of the dishwasher 10 becomes necessary, this task is readily facilitated by virtue of the fact that the front and rear slide tracks 86 and 87, respectively, are both easily and directly removable with a minimum of effort. In the case of front slide track 86 all that is required is that the aforementioned fiat head machine screws 90 be unscrewed from their associated nuts 91 whereas with rear slide track 87 there is a need only to loosen by hand the wing nuts threaded on the weld studs 93. To replace the tracks 86 and 87 upon completion of the cleaning task, the reverse procedure is followed.

Thus, there has been prov lded a novel and improved conveyor chain and track assembly for commercial dishwashers wherein both the front and rear slide tracks for the dish racks are directly removable with a minimum of effort thereby facilitating the cleaning of the conveyor chain and track assembly as well as the interior and the rearwardly positioned components of the dishwasher. Further the conveyor chain being located directly below the rear track wherein it rides on a separate chain support rail, it in no way interferes with the lower pumped wash as does a center chain drive or center pawl drive. Finally, inasmuch as all the moving parts of the conveyor chain are located at the rear of the dishwasher there is less likelihood of the possibility of any injury occurring to personnel due to their coming into contact with such moving parts while the dishwasher is operating.

While only one embodiment of our invention has been shown, it will be appreciated that many modifications thereof may readily be made by those skilled in the art, some of which have been previously indicated hereinabove. We therefore intend by the appended claims to cover the above modifications as well as all other modifications which fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. For use in a dishwasher having at least one wash compartment, a front wall, a rear wall, and a pair of opposed end walls, a conveyor chain and track assembly comprising:

a. a pair of slide tracks for slideably receiving at least one dish rack at a time thereon for movement relative thereto in a horizontal plane;

b. first means mounting one of said pair of slide tracks within said dishwasher adjacent said front wall of said dishwasher, said one of said pair of slide tracks being readily detachable from said first mounting means;

c. second means mounting the other of said pair of slide tracks within said dishwasher adjacent said rear wall of said dishwasher, said other of said pair of slide tracks being readily detachable from said second mounting means;

d. a single conveyor chain having a plurality of lugs positioned thereon;

chain support means for supporting said single conveyor chain for rotational movement in a vertical plane, said chain support means including an upper rail section and a lower rail section;

. means supporting said chain support means adjacent said rear wall of said dishwasher with said upper rail section of said chain support means positioned below and in substantially close proximity to said other of said pair of slide tracks and with said lower rail section of said chain sup port means positioned below and in substantially aligned, spaced relation to said upper rail section of said chain support means;

g. at least one of said plurality of lugs protruding at any given time above the level of said other of said pair of slide tracks so as to be capable of engaging and moving a dish rack horizontally in slideably supported relation on said pair of slide tracks through said wash compartment of said dishwasher; and

h. at least another of said plurality of lugs at any given time extending downwardly'below the level of said lower rail section adjacent to the edge thereof.

2. For use in a dishwasher as set forth in claim 1, a conveyor chain and track assembly wherein;

a. said first mounting means includes a first pair of support brackets fastened to said pair of opposed end walls of said dishwasher adjacent said front wall of said dishwasher; and

b. said one of said pair of slide tracks includes fastening means carried at either end thereof cooperable with said first pair of support brackets to detachably retain said one of said pair of slide tracks on said pair of opposed end walls in substantially juxtaposed relation to said front wall of said dishwasher.

3. For use in a dishwasher as set forth in claim 2, a conveyor chain and track assembly wherein:

a. said one of said pair of slide tracks is readily detachable with minimum use of tools from said first mounting means; and

b. said other of said pair of slide tracks is readily detachable solely by hand from said second mounting means.

4. For use in a dishwasher as set forth in claim 1, a conveyor chain and track assembly wherein:

a. said chain support means further includes a medial portion interconnecting said upper rail section to said lower rail section;

b. said upper rail section of said chain support means supports the drive run of said single conveyor chain; and

c. said lower rail section of said chain support means supports the return run of said single conveyor chain.

5. For use in a dishwasher as set forth in claim 4, a conveyor chain and track assembly wherein:

a. said chain support means further includes means supported on and extending outwardly from said medial portion of said chain supporting means to substantially enclose said return run of said single conveyor chain to prevent accidental contact by personnel with said return run of said single conveyor chain; and

b. said lower rail section is of a lesser width than said upper rail section to permit said lugs on said return run of said single conveyor chain to travel along the edge of said lower rail section unobstructed. 

1. For use in a dishwasher having at least one wash compartment, a front wall, a rear wall, and a pair of opposed end walls, a conveyor chain and track assembly comprising: a. a pair of slide tracks for slideably receiving at least one dish rack at a time thereon for movement relative thereto in a horizontal plane; b. first means mounting one of said pair of slide tracks within said dishwasher adjacent said front wall of said dishwasher, said one of said pair of slide tracks being readily detachable from said first mounting means; c. second means mounting the other of said pair of slide tracks within said dishwasher adjacent said rear wall of said dishwasher, said other of said pair of slide tracks being readily detachable from said second mounting means; d. a single conveyor chain having a plurality of lugs positioned thereon; e. chain support means for supporting said single conveyor chain for rotational movement in a vertical plane, said chain support means including an upper rail section and a lower rail section; f. means supporting said chain support means adjacent said rear wall of said dishwasher with said upper rail section of said chain support means positioned below and in substantially close proximity to said other of said pair of slide tracks and with said lower rail section of said chain support means positioned below and in substantially aligned, spaced relation to said upper rail section of said chain support means; g. at least one of said plurality of lugs protruding at any given time above the level of said other of said pair of slide tracks so as to be capable of engaging and moving a dish rack horizontally in slideably supported relation on said pair of slide tracks through said wash compartment of said dishwasher; and h. at least another of said plurality of lugs at any given time extending downwardly below the level of said lower rail section adjacent to the edge thereof.
 2. For use in a dishwasher as set forth in claim 1, a conveyor chain and track assembly wherein; a. said first mounting means includes a first pair of support brackets fastened to said pair of opposed end walls of said dishwasher adjacent said front wall of said dishwasher; and b. said one of said pair of slide tracks includes fastening means carried at either end thereof cooperable with said first pair of support brackets to detachably retain said one of said pair of slide tracks on said pair of opposed end walls in substantially juxtaposed relation to said front wall of said dishwasher.
 3. For use in a dishwasher as set forth in claim 2, a conveyor chain and track assembly wherein: a. said one of said pair of slide tracks is readily detachable with minimum use of tools from said first mounting means; and b. said other of said pair of slide tracks is readily detachable solely by hand from said second mounting means.
 4. For use in a dishwasher as set forth in claim 1, a conveyor chain and track assembly wherein: a. said chain support means further includes a medial portion interconnecting said upper rail section to said lower rail section; b. said upper rail section of said chain support means supports the drive run of said single conveyor chain; and c. said lower rail section of said chain support means supports the return run of said single conveyor chain.
 5. For use in a dishwasher as set forth in claim 4, a conveyor chain and track assembly wherein: a. said chain support means further includes means supported on and extending outwardly from said medial portion of said chain supporting means to substantially enclose said return run of said single conveyor chain to prevent accidental contact by personnel with said return run of said single conveyor chain; and b. said lower rail section is of a lesser width than said upper rail section to permit said lugs on said return run of said single conveyor chain to travel along the edge of said lower rail section unobstructed. 